Design of hybrid-coupled multiplexers and diplexers using asymmetrical superconducting filters

The feasibility of building high-temperature superconducting (HTS) hybrid-coupled multiplexers and diplexers employing filters with asymmetrical frequency characteristics is demonstrated. The design of pseudo-interdigital filters with improved skirt performance is discussed. Experimental and theoretical results are presented for superconducting filters, hybrids, and a fully integrated C-band diplexer. It is noted that the extra coupling which exists between nonadjacent resonators in pseudo-interdigital filters may be used to improve the rejection performance on the high-frequency skirt. Filters with such rejection performance are suitable for use in the design of HTS hybrid-coupled multiplexers and diplexers. The experimental results reported here for superconducting filters, hybrids and the fully integrated C-band diplexer demonstrate the possibility of building such components with no tuning elements.<>